JP2003201848A - Engine intake system - Google Patents

Abstract

(57) [Summary] An unburned gas HC (hydrocarbon) at the time of a low temperature start by suppressing the fuel adhesion to an inner wall of an intake port of an engine by wrapping fuel injected from a fuel injector with intake air to suppress fuel adhesion to an inner wall of an intake port of an engine. To provide an intake device for an engine capable of suppressing generation of air. A control valve is provided in an independent intake pipe for distributing air to each cylinder of the engine from a collector of an intake manifold, the control valve varying an opening projected area to an intake port of the engine through which fuel is injected from a fuel injector. In the intake system for an engine, which controls the amount of supply air by controlling the opening degree of the control valve according to the operating conditions, an airflow is formed on an inner wall surface of an intake port of the engine, and fuel injected from a fuel injector is supplied to the engine. So that it does not directly hit the inner wall surface of the intake port. [Effect] Atomization can be stabilized in the injected fuel at the time of low temperature start.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine intake system, and more particularly, to a control valve for controlling the tumble flow in a cylinder by dividing air supplied to an intake port of the engine by providing a bypass passage. An intake device for an engine capable of forming an air guard on the inner wall surface of the intake port of the engine so that the fuel injected from the fuel injector does not directly contact the inner wall surface of the intake port of the engine when the control valve is fully closed. .

[0002]

2. Description of the Related Art Conventionally, for the purpose of stabilizing combustion, a control valve for controlling air supplied to an intake port of an engine in order to promote generation of a tumble flow in a cylinder,
It is provided near the entrance of the engine intake port. The control valve that controls the tumble flow in the cylinder promotes the generation of the tumble flow in the cylinder by the biased flow velocity that is supplied through the bypass passage side when the main passage side is fully closed. As similar techniques, for example, JP-A-5-202829 and JP-A-6-159.
078, JP-A-10-89200, JP-A-9-68047 and the like.

[0003]

Conventionally, a control valve for controlling the air supplied to the intake port of the engine is provided near the inlet of the intake port of the engine to stabilize the combustion of the fuel supplied into the engine. This is because For this reason, when the main passage is closed, due to the uneven flow supplied to the engine through the bypass passage, the flow of the tumble flow generated in the cylinder is strengthened and the fuel atomization is promoted. .

Further, generally, the fuel injector is arranged so that the fuel can be injected into the intake port of the engine so that the fuel injection direction of the fuel injector hits the intake valve. However, the fuel injected from the fuel injector spreads in a mist state in the intake port of the engine after being injected and adheres to the inner wall surface of the intake port of the engine. Therefore, at the time of cold start of the engine, the fuel adhering to the inner wall surface of the intake port of the engine becomes droplets and enters the cylinder between the intake valves,
There is a problem that the gas cannot be completely vaporized and the concentration of unburned gas HC (hydrocarbon) in the exhaust gas becomes high.

According to the present invention, by enclosing the fuel injected from the fuel injector with intake air, the adhesion of the fuel to the inner wall of the intake port of the engine is suppressed, so that unburned gas HC (hydrocarbon) is generated at the time of low temperature starting. It is an object of the present invention to provide an intake device for an engine capable of suppressing the above.

[0006]

To achieve the above object, one of the features of the present invention is that fuel is supplied from a fuel injector in the middle of an independent intake pipe that distributes air from a collector of an intake manifold to each cylinder of an engine. An engine intake device for controlling an amount of supply air by providing a control valve for varying an opening projected area of an injection port of an engine to an intake port of the engine and controlling an opening of the control valve according to an operating condition of the engine. An air flow is formed on the inner wall surface of the intake port so that fuel injected from the fuel injector does not directly hit the inner wall surface of the intake port of the engine.

In order to achieve the above object, another feature of the present invention is that a main passage and a bypass passage are provided for each cylinder of the engine, and the opening projected area of the engine intake port is changed on the main passage side. A valve body with a control valve is installed in the middle of an independent intake pipe that distributes air from the collector of the intake manifold to each cylinder of the engine, the control valve is controlled to open and close according to the operating conditions of the engine, and the control valve is fully closed. In the intake system of an engine that increases the air flow rate on the bypass passage side to promote the generation of tumble flow in the cylinder when the valve is operated in the above state, the control valve is fully closed on the side opposite to the side where the bypass passage is formed. Sometimes it is formed so that there is a clearance between it and the inner wall surface of the valve body. Configured to flow into the engine intake port.

In order to achieve the above-mentioned object, still another feature of the present invention is that a main passage and a bypass passage are provided for each cylinder of the engine, and the opening projected area of the engine intake port is variable on the main passage side. A valve body with a control valve is installed in the middle of an independent intake pipe that distributes air from the intake manifold collector to each cylinder of the engine, and the control valve is controlled to open and close according to the operating conditions of the engine, and the control valve is fully closed. In the intake device of the engine that increases the air flow rate on the bypass passage side to promote the generation of the tumble flow in the cylinder when the valve body is operated in the state, the second side is provided on the side opposite to the side where the bypass passage of the valve body is formed. The bypass passage is formed so that air flows into the engine intake port through the second bypass passage when the control valve is fully closed. It is configured.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of an intake system for an engine according to the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view of an engine intake device configured by providing a valve body between an intake manifold and an intake port of the engine, and FIG. 2 is air when a control valve provided in the valve body shown in FIG. 1 is fully closed. FIG. 3 is a left side view of the valve body shown in FIG. 2, and FIG. 4 is a flow diagram of the air when the control valve provided in the valve body shown in FIG. 1 is fully opened. FIG. 5 is a left side view of the valve body shown in FIG. 4, and FIG. 6 is a diagram showing a positional relationship of the downstream open end of the bypass passage of the valve body shown in FIG. 1 to the injection area of the injector. FIG. 7 shows the position of the intersection point between the bypass flow of the bypass passage of the valve body shown in FIG. 1 and the inner wall surface of the intake port of the engine, the position of the intersection point of the fuel injection area of the injector and the inner wall surface of the intake port of the engine. Is a graph showing the relationship.

In FIG. 1, reference numeral 100 denotes an intake manifold, which is provided with an independent intake pipe 102 for distributing the air supplied from a collector 101 to each cylinder of the engine. An intake port 203, which is directly connected to an intake port 202 of a cylinder 201 of an engine 200 via a valve body 1, is attached to a tip of an independent intake pipe 102 of the intake manifold 100. Reference numeral 204 is an intake valve attached to the intake port 202.

The valve body 1 is formed in a tubular shape and has a main passage 2 and a bypass passage 3, and the air supplied from the collector 101 by the main passage 2 and the bypass passage 3 is supplied to the intake port 203 of the engine 200. The intake passage is formed. Main passage 2 of valve body 1
A control valve 4 that is opened and closed according to the operating condition of the engine is provided therein. The bypass passage 3 supplies a flat flow (bypass flow 3A) having a high flow velocity when the control valve 4 is fully closed.
Enter the cylinder 201 and generate a tumble flow in the cylinder 201.

The control valve 4 is shown in FIGS.
When the valve body 1 is in the fully closed state, the valve body 1 comes into contact with the inner wall surface of the bypass passage 3 side, and a clearance L is formed on the side of the valve body 1 opposite to the side where the bypass passage 3 is formed. . The bypass passages 3 are arranged one on each side of the fuel injector 10 with the fuel injector 10 interposed therebetween. When the control valve 4 is fully closed, the engine is not sufficiently warmed up at the time of starting (A
/ F is reduced).

When the control valve 4 is fully closed as shown in FIGS. 2 and 3, the bypass passage 3 of the valve body 1 is closed.
3A, the bypass flow 3A is supplied to the intake port 203 of the engine 200, and is supplied to the cylinder 201 along the intake port wall surface 203A. And this bypass flow 3
A enters the cylinder 201 from the intake port 203 to generate a tumble flow. Further, in the main passage 2, a flat stream 2A is supplied to the intake port 203 of the engine 200 from a clearance L formed on the inner wall surface of the control valve 4 and the valve body 1, and is supplied to the cylinder 201 along the intake port wall surface 203A. Supplied. Then, the flat stream 2A becomes a wall flow of the intake port 203 and enters the cylinder 201.

An injector mounting portion 5 is formed on the upper portion of the valve body 1, and a fuel injector 10 is mounted on the injector mounting portion 5. The fuel injection direction of the fuel injector 10 is directed to an intake valve 204 provided at the intake port 202. 11 is a fuel injector 10
Is a fuel injection region in which the fuel sprayed from the fuel injection nozzle spreads in a mist state.

When the engine is started and it is not necessary to make the fuel rich, the control valve 4 is changed from the fully closed state shown in FIGS. 2 and 3 to the fully opened state shown in FIGS. 4 and 5. Then, since the main passage 2 is not blocked by the control valve 4, the air supplied from the intake manifold 100 flows into the main passage 2 and the bypass passage 3 separately and is supplied to the intake port 203 of the engine 200. To be done.

As described above, when the control valve 4 is fully opened as shown in FIGS. 4 and 5, the bypass passage 3 with respect to the main passage 2 for the air supplied to the intake port 203 of the engine 200 through the valve body 1 is provided. The flow rate ratio is as follows: when the control valve 4 is fully opened, the flow rate of the main passage 2 is: the flow rate of the bypass passage 3 = large: small, and when the control valve 4 is fully closed, the flow rate of the main passage 2: the flow rate of the bypass passage 3 = small: When the control valve 4 has an intermediate opening degree, the flow rate of the main passage 2 is set to the flow rate of the bypass passage 3 = medium: medium.

The downstream open end 3 of the bypass passage 3
As shown in FIG. 6, 1 is arranged on the intake port wall surface 203A side of the intake port 203 of the engine 200 with respect to the injection region 11 of the fuel injector 10. With this configuration, the intake port wall surface 203A of the injection region 11 of the fuel injected from the fuel injector 10
An air guard can be formed on the side.

The bypass passage 3 is, as shown in FIG. 7, a bypass flow 3A supplied through the bypass passage 3.
Intersection D of the engine and the intake port wall surface 203A of the engine 200
Is arranged upstream of the intersection E between the fuel injection region 11 of the fuel injector 10 and the intake port wall surface 203A of the engine 200. With this configuration, an air guard can be formed on the intake port wall surface 203A side of the injection region 11 of the fuel injected from the fuel injector 10.

FIGS. 8 to 14 show a second embodiment of the intake system for an engine according to the present invention. 8 is a sectional view of the control valve provided in the valve body when it is fully opened, FIG. 9 is a left side view of the valve body shown in FIG. 8, and FIG.
0 is a sectional view when the control valve provided in the valve body is fully closed, FIG. 11 is a left side view of the valve body shown in FIG. 10, and FIG. 12 is a control valve provided in the valve body for controlling the main passage FIG. 13 is a diagram showing a state in which a clearance is formed between the control valve and the inner wall surface of the valve body, FIG. 13 is a left side view of the valve body shown in FIG. 12, and FIG. 14 is FIGS.
FIG. 3 is an overall perspective view of a control valve provided in the valve body shown in FIG.

The second embodiment shown in FIGS. 8 to 14 differs from the first embodiment shown in FIGS. 1 to 7 in that the first embodiment shown in FIGS. While the control valve of FIG. 8 is a valve body formed in a plate shape,
The control valve of the illustrated second embodiment is formed in a cylindrical shape, and the cylindrical control valve is fitted so as to be orthogonal to the cylindrical valve body.

In FIGS. 8 and 9, the valve body 1 is
It is formed in a tubular shape and has a main passage 2 and a bypass passage 3. The main passage 2 and the bypass passage 3 form a collector 1
An intake passage is formed to supply the air supplied from 01 to the intake port 203 of the engine 200. The bypass passages 3 of the valve body 1 are arranged one on each side of the fuel injector 10 with the fuel injector 10 interposed therebetween. The control valve 4 is in the fully closed state when the engine is not sufficiently warmed up at the time of starting (when reducing the A / F). A control valve 20 formed as shown in FIG. 14 is rotatably fitted in the main passage 2 of the valve body 1. This control valve 20 is shown in FIG.
As shown in FIG. 3, a through hole 21 is formed in a columnar shape and is electrically connected to the main passage 2 in a direction orthogonal to the length direction.

The main passage 2 is configured to open and close the main passage 2 by rotating a control valve 20 fitted in the valve body 1. When this control valve 20 is rotated 90 °, as shown in FIGS.
The main passage 2 is fully closed. When the main passage 2 is fully closed, in the valve body 1, a flat flow having a high flow velocity (bypass flow 3A) is supplied to the intake port 203 of the engine 200 only from the bypass passage 3 and is supplied from the bypass passage 3. The bypass flow 3A enters the cylinder 201 to generate a tumble flow in the cylinder 201.

Further, the control valve 20 is rotated by an angle smaller than 90 °, and as shown in FIGS.
When the opening passage 22 is formed below the control valve 20 on the downstream side of the bypass passage 3, the opening passage 23 is formed above the control valve 20 on the upstream side of the bypass passage 3. In this way, the opening passages 22 are
23 is formed, the bypass passage 3 of the valve body 1 is formed.
3A, the bypass flow 3A is supplied to the intake port 203 of the engine 200, and is supplied to the cylinder 201 along the intake port wall surface 203A. And this bypass flow 3
A enters the cylinder 201 from the intake port 203 to generate a tumble flow.

Further, in the main passage 2, the control valve 20
The flat stream 2A flowing from the upper open passage 23 of the control valve 20 passes through the through hole 21 of the control valve 20, flows from the lower open passage 22 of the control valve 20, and is supplied to the intake port 203 of the engine 200. The flat stream 2A supplied to the intake port 203 of the engine 200 is
It is supplied to the cylinder 201 along A, and this flat stream 2A becomes the wall flow of the intake port 203 and enters the cylinder 201.

The opening of the control valve 20 is controlled so that the air flow rate in the main passage 2 is maximized when the load is high and the air flow rate in the bypass passage 3 is maximized when the load is low. Due to the presence of the uneven flow rate, the tumble flow in the cylinder 200 is promoted to improve fuel efficiency.

FIGS. 15 to 18 show a third embodiment of the engine intake device according to the present invention. Figure 1
5 is a sectional view when the control valve provided in the valve body is fully closed, FIG. 16 is a left side view of the valve body shown in FIG. 15, and FIG. 17 is a sectional view when the control valve provided in the valve body is fully opened. 18 is a left side view of the valve body shown in FIG.

The third embodiment shown in FIGS. 15 to 18 is different from the first embodiment shown in FIGS. 1 to 7 in that the first embodiment shown in FIGS. Forms a clearance between the control valve 4 and the inner wall surface of the bypass passage 3 when the control valve is fully closed, and when the control valve is fully closed, the bypass flow 3A flows from the bypass passage 3 into the intake port 203 of the engine 200. While the flat flow 2A is supplied from the clearance between the control valve 4 and the inner wall surface of the bypass passage 3, in the present embodiment, the bypass passage 3 is provided above the valve body and The second bypass passage 6 is provided on the side, the air flow is formed on the inner wall surface of the intake port of the engine by the two upper and lower flat flows, and the fuel injected from the fuel injector does not directly contact the inner wall surface of the intake port of the engine. It is obtained so as to form a sea urchin Eagado.

15 and 16, the valve body 4
0 is formed in a tubular shape and has a main passage 41, a bypass passage 42, and a second bypass passage 43.
The air supplied from the collector 101 through the bypass passage 42 and the second bypass passage 43 is supplied to the engine 20.
An intake passage that supplies 0 to the intake port 203 is formed. In the main passage 41 of the valve body 40, a control valve 44 that is opened / closed according to the operating conditions of the engine is openably / closably provided. The bypass passage 22 and the second bypass passage 43 supply a flat flow (a bypass flow 42A, 43A) having a high flow velocity when the control valve 44 is fully closed, and the bypass flow 42A, 43A is supplied to the cylinder 20.
1, and a tumble flow is generated in the cylinder 201.

When the engine is started and it is not necessary to make the fuel rich, the control valve 44 changes from the fully closed state shown in FIGS. 15 and 16 to the fully opened state shown in FIGS. 17 and 18. Then, since the main passage 41 is not blocked by the control valve 44, the air supplied from the intake manifold 100 is divided into the main passage 41, the bypass passage 42, and the second bypass passage 43, and flows into the engine. 200 is supplied to the intake port 203.

As described above, the control valve 44 has the same structure as that shown in FIGS.
8 shows a bypass passage 42 for the main passage 41 and a second passage of the air supplied to the intake port 203 of the engine 200 via the valve body 40 when fully opened.
When the control valve 44 is fully opened, the flow rate ratio of the bypass passage 43 becomes as follows: flow rate of the main passage 41: (flow rate of the bypass passage 42 and the second bypass passage 43) = large: small, and when the control valve 44 is fully closed, Flow rate of the main passage 41: (flow rate of the bypass passage 42 and the second bypass passage 43) = small: large When the control valve 44 has an intermediate opening degree, flow rate of the main passage 41: (bypass passage 42 and the second bypass passage 42 The flow rate in the bypass passage 43) = medium: Medium.

The downstream open end 31 of the bypass passage 42 is arranged on the intake port wall surface 203A side of the intake port 203 of the engine 200 with respect to the injection region 11 of the fuel injector 10, as in FIG. With this configuration, an air guard can be formed on the intake port wall surface 203A side of the injection region 11 of the fuel injected from the fuel injector 10.

Further, in the bypass passage 42, the intersection of the bypass flow 42A supplied through the bypass passage 42 and the intake port wall surface 203A of the engine 200 is the intersection of the fuel injection region 11 of the fuel injector 10 and the engine 200, as in FIG. It is arranged upstream from the intersection with the intake port wall surface 203A. With this configuration, the injection region 1 of the fuel injected from the fuel injector 10
An air guard can be formed on the side of the intake port wall surface 203A of No. 1.

[0033]

As described above, according to the engine intake system of the present invention, by enclosing the fuel injected from the fuel injector with the intake air, it is possible to suppress the adhesion of the fuel to the inner wall of the intake port of the engine. It is possible to suppress the generation of unburned gas HC (hydrocarbon) during low temperature starting.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an intake device for an engine configured by providing a valve body between an intake manifold and an intake port of the engine.

FIG. 2 is a cross-sectional view for explaining an air flow when a control valve provided in the valve body shown in FIG. 1 is fully closed.

FIG. 3 is a left side view of the valve body shown in FIG.

FIG. 4 is a cross-sectional view for explaining the flow of air when the control valve provided in the valve body shown in FIG. 1 is fully opened.

5 is a left side view of the valve body shown in FIG.

FIG. 6 is a diagram showing a positional relationship between a downstream open end of a bypass passage of the valve body shown in FIG. 1 and an injector injection region.

FIG. 7 shows the positional relationship between the intersection point position of the bypass flow in the bypass passage of the valve body shown in FIG. 1 and the inner wall surface of the intake port of the engine, the fuel injection area of the injector, and the intersection point position of the inner wall surface of the intake port of the engine. FIG.

FIG. 8 is a cross-sectional view when a control valve provided in the valve body is fully opened.

9 is a left side view of the valve body shown in FIG.

FIG. 10 is a cross-sectional view when a control valve provided in a valve body is fully closed.

11 is a left side view of the valve body shown in FIG.

FIG. 12 is a diagram showing a state in which a control valve provided in a valve body is controlled to form a clearance in the main passage and an inner wall surface of the valve body.

13 is a left side view of the valve body shown in FIG.

FIG. 14 is an overall perspective view of a control valve provided in the valve body shown in FIGS.

FIG. 15 is a cross-sectional view when a control valve provided in the valve body is fully closed.

16 is a left side view of the valve body shown in FIG.

FIG. 17 is a cross-sectional view of the control valve provided on the valve body when it is fully opened.

18 is a left side view of the valve body shown in FIG.

[Explanation of symbols]

1 ……………… Valve body 2 ……………… Main passage 3 ……………… Bypass passage 4 ……………… Control valve 10 ……………… Fuel injector 11 ……………… Fuel injection area 20 ……………… Control valve 40 ……………… Valve body 41 ……………… Main passage 42 ......... Bypass passage 43 ……………… Second bypass passage 200 ………… Engine 201 ………… Cylinder 203 ………… Intake port 203A ... Wall of intake port

Claims (9)

[Claims] 1. A control valve is provided in the middle of an independent intake pipe that distributes air from an intake manifold collector to each cylinder of the engine, and a control valve that varies an opening projection area to an intake port of an engine where fuel is injected from a fuel injector, In an engine intake device that controls the amount of supply air by controlling the opening of the control valve according to the operating conditions of the engine, forming an air flow on the inner wall surface of the intake port of the engine,
An intake system for an engine, characterized in that fuel injected from the fuel injector does not directly contact an inner wall surface of an intake port of the engine. 2. A main body and a bypass passage are provided for each cylinder of the engine, and a valve body having a control valve for varying the opening projected area of the engine intake port is provided on the main passage side, and a valve body is provided from the collector of the intake manifold to the engine. The air flow rate on the bypass passage side when the control valve is opened / closed according to the operating conditions of the engine and the control valve is operated in a fully closed state, provided in the middle of an independent intake pipe that distributes air to each cylinder In the intake device of the engine for increasing the generation of the tumble flow in the cylinder, the control valve is provided on the side opposite to the side where the bypass passage is formed and at the time of fully closing the clearance between the control valve and the inner wall surface of the valve body. When the control valve is fully closed, air is introduced through the clearance into the engine intake port. An intake device for an engine is characterized in that so as to flow into. 3. The intake system for an engine according to claim 2, wherein the amount of air flowing into the engine intake port through the clearance is an amount commensurate with the flow rate of air in the bypass passage. 4. A main body and a bypass passage are provided for each cylinder of an engine, and a valve body having a control valve for varying an opening projected area of an engine intake port is provided on the main passage side, and a valve body is provided from a collector of an intake manifold to an engine. The air flow rate on the bypass passage side when the control valve is opened / closed according to the operating conditions of the engine and the control valve is operated in a fully closed state, provided in the middle of an independent intake pipe that distributes air to each cylinder In the intake device of the engine for increasing the generation of the tumble flow in the cylinder, a second bypass passage is formed on the side of the valve body opposite to the side where the bypass passage is formed. The air is allowed to flow into the engine intake port through the second bypass passage when closed. Jin of the intake system. 5. The bypass passage is provided in the vicinity of the injector mounting portion, and the clearance forming portion is provided at a position facing the bypass passage side.
The intake system for an engine according to 3 or 4. 6. The intake system for an engine according to claim 2, wherein the bypass passages are arranged one on each side of the injector so as to sandwich the injector therebetween. 7. The intake device for an engine according to claim 2, wherein the downstream open end of the bypass passage is arranged on the wall surface side of the intake port of the engine with respect to the injection region of the injector. 8. In the bypass passage, an intersection of a bypass flow supplied through the bypass passage and an inner wall surface of an intake port of the engine is located upstream of an intersection of a fuel injection area of the injector and an inner wall surface of the intake port of the engine. The intake device for an engine according to claim 2, 3 or 4, wherein the intake device is arranged in the. 9. The flow rate ratio of the air supplied to the intake port of the engine via the valve body to the main passage is such that when the valve is fully opened, the flow rate of the main passage: flow rate of the bypass passage = large: small, The flow rate of the main passage: the flow rate of the bypass passage = small: large when fully closed, and the flow rate of the main passage: the flow rate of the bypass passage = medium: middle when the valve intermediate opening is set. 3, 4,
The intake system for an engine according to 5, 6, 7 or 8.